Gate valve with full-bore protective sleeve

ABSTRACT

A gate valve adapted for use in oil and gas operations, such as, for example, fracturing or gravel-packing operations. In an exemplary embodiment, the gate valve includes a valve body, which defines an internal region; a first fluid bore intersecting the internal region and defining a first interior surface in the valve body; and a first annular recess formed in the first interior surface and adjoining the internal region. A first seat element defines a second fluid bore and extends within the first annular recess. A first protective sleeve extends between respective portions of the first seat element and the valve body. The first and second fluid bores have first and second full-bore inside diameters, respectively. The first protective sleeve has a third full-bore inside diameter that is substantially equal to each of the first and second full-bore inside diameters.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/396,941, filed Jan. 3, 2017, the entire disclosure of which is herebyincorporated herein by reference U.S. patent application Ser. No.15/396,941 claims priority to, and the benefit of the filing date of,U.S. patent application No. 62/274,421, filed Jan. 4, 2016, the entiredisclosure of which is hereby incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates in general to valves and, in particular,to gate valves used in oil and gas operations.

BACKGROUND

A gate valve may be used in oil and gas operations such as, for example,hydraulic fracturing operations. Fluidic materials may flow through thegate valve at high flow rates and pressures. As a result of beingsubjected to this type of flow over time, in some cases one or morecomponents of the gate valve, such as sealing elements or othercomponents, may experience structural degradation or failure such as,for example, blowout, wear-out, and/or deterioration. This structuraldegradation or failure may require the replacement of the entire gatevalve. Therefore, what is needed is a gate valve or method thataddresses one or more of the foregoing issues, and/or one or more otherissues.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional perspective view of a gate valve includinga valve body, a valve seat, a gate assembly, an operating end, and abalancing end, according to an exemplary embodiment.

FIG. 1B is a cross-sectional elevational view of the gate valve of FIG.1A, including the valve body, the valve seat, the gate assembly, theoperating end, and the balancing end, according to an exemplaryembodiment.

FIG. 2 is a cross-sectional view of the valve body of FIGS. 1A and 1B,according to an exemplary embodiment.

FIG. 3 is a cross-sectional exploded view of the valve seat of FIGS. 1Aand 1B, according to an exemplary embodiment.

FIG. 4 is a cross-sectional view of the gate assembly of FIGS. 1A and1B, according to an exemplary embodiment.

FIG. 5 is a cross-sectional view of the operating end of FIGS. 1A and1B, according to an exemplary embodiment.

FIG. 6 is a cross-sectional view of the balancing end of FIGS. 1A and1B, according to an exemplary embodiment.

FIG. 7 is a cross-sectional view of the gate valve of FIGS. 1A-6 in anopen configuration, the gate valve including the valve body, the valveseat, the gate assembly, the operating end, and the fluid end, accordingto an exemplary embodiment.

FIG. 8A is an enlarged view of a portion of the cross-sectional view ofFIG. 7, according to an exemplary embodiment.

FIG. 8B is a view similar to that of FIG. 8A but depicting the gatevalve in a closed configuration, according to an exemplary embodiment.

DETAILED DESCRIPTION

Referring initially to FIGS. 1A and 1B, an exemplary embodiment of agate valve, generally referred to by the reference numeral 10, isillustrated. The gate valve 10 includes a valve body 12; a valve seat 14engaged with the valve body 12; a gate assembly 16 extending within thevalve body 12 and accommodated by the valve seat 14; an operating end 18connected to the valve body 12; and a balancing end 20 connected to thevalve body 12, opposite the operating end 18. The gate assembly 16 isenclosed within the valve body 12, the operating end 18, and thebalancing end 20. The operating end 18 is adapted to actuate the gateassembly 16 between an open configuration, in which a fluid is permittedto flow through the valve body 12, and a closed configuration, in whichthe fluid is restricted from flowing through the valve body 12. Thebalancing end 20 accommodates a portion of the gate assembly 16 andbalances axial forces such as, for example, hydraulic lift forces, whichare exerted on the gate assembly 16 during operation of the gate valve10. As will be described in further detail below, in an exemplaryembodiment, the valve seat 14 includes two sets of identical componentspositioned on either side of the gate assembly 16, and maintains theaxial alignment of the gate assembly 16 during the actuation thereofbetween the open and closed configurations.

Referring now to FIG. 2, with continuing reference to FIGS. 1A and 1B,an exemplary embodiment of the valve body 12 is illustrated. The valvebody 12 includes an internal region 22, such as, for example, a passageor bore, extending therethrough along a longitudinal center axis 24 anddefining an interior surface 26 in the valve body 12. A fluid bore 28extends through the valve body 12 along a longitudinal center axis 30and intersects the internal region 22. The fluid bore 28 has a full-boreinside diameter D1 and defines an interior surface 32 in the valve body12. The full-bore inside diameter D1 is a “full-bore inside diameter”because it is unimpeded along the interior surface 32, as shown in FIG.2. In several exemplary embodiments, the longitudinal center axis 30 ofthe fluid bore 28 is substantially perpendicular to the longitudinalcenter axis 24 of the internal region 22.

Annular recesses 34 and 36 are formed in the interior surface 32. Theannular recess 34 adjoins the internal region 22 and defines an interiorsurface 38 and an annular shoulder 40 in the valve body 12. The interiorsurface 38 adjoins both the annular shoulder 40 and the interior surface26 of the valve body 12. The annular recess 36 adjoins the annularrecess 34. Moreover, the annular recess 36 has an inside diameter D2that is less than the inside diameter of the annular recess 34. Theinside diameter D2 of the annular recess 36 is greater than thefull-bore inside diameter D1 of the fluid bore 28. The annular recess 36defines an interior surface 42 and an annular shoulder 44 in the valvebody 12. The annular shoulder 44 adjoins the interior surface 32 of thevalve body 12. Further, the interior surface 42 adjoins both the annularshoulder 44 and the annular shoulder 40.

Additionally, a fluid bore 46 extends through the valve body 12 along alongitudinal center axis 48 and intersects the internal region 22. Thefluid bore 46 has a full-bore inside diameter D3 and defines an interiorsurface 50 in the valve body 12. The full-bore inside diameter D3 is a“full-bore inside diameter” because it is unimpeded along the interiorsurface 50, as shown in FIG. 2. In several exemplary embodiments, thelongitudinal center axis 48 of the fluid bore 46 is substantiallyperpendicular to the longitudinal center axis 24 of the internal region22. Moreover, in several exemplary embodiments and as shown in FIG. 2,the longitudinal center axes 30 and 48 of the inlet and fluid bores 28and 46, respectively, are substantially co-axial.

Annular recesses 52 and 54 are formed in the interior surface 50. Theannular recess 52 adjoins the internal region 22 and defines an interiorsurface 56 and an annular shoulder 58 in the valve body 12. The interiorsurface 56 adjoins both the annular shoulder 58 and the interior surface26 of the valve body 12. The annular recess 54 adjoins the annularrecess 52. Moreover, the annular recess 54 has an inside diameter D4that is less than the inside diameter of the annular recess 52. Theinside diameter D4 of the annular recess 54 is greater than thefull-bore inside diameter D3 of the fluid bore 46. The annular recess 54defines an interior surface 60 and an annular shoulder 62 in the valvebody 12. The annular shoulder 62 adjoins the interior surface 50 of thevalve body 12. Further, the interior surface 60 adjoins both the annularshoulder 62 and the annular shoulder 58. In several exemplaryembodiments, the full-bore inside diameter D1 is equal to the full-boreinside diameter D3. In several exemplary embodiments, the insidediameter D2 is equal to the inside diameter D4. In several exemplaryembodiments, the inside diameters D1 and D2 are equal to the insidediameters D3 and D4, respectively.

Referring to FIG. 3, with continuing reference to FIGS. 1A and 1B, anexemplary embodiment of the valve seat 14 is illustrated. The valve seat14 includes a pair of seat elements 64 a and 64 b, a corresponding pairof protective sleeves 65 a and 65 b, and a corresponding pair of gateguides 66 a and 66 b, respectively. The seat element 64 a is a generallycylindrical member defining a pair of opposing faces 64 aa and 64 ab.Similarly, the seat element 64 b is a generally cylindrical memberdefining a pair of opposing faces 64 ba and 64 bb. In several exemplaryembodiments, the seat elements 64 a and 64 b are substantially identicalto one another.

The seat element 64 a includes an annular groove 68 a formed in the face64 aa thereof. The annular groove 68 a is adapted to accommodate anannular seal 68 b. Further, an annular ridge 70 extends radially outwardfrom the exterior of the seat element 64 a. In several exemplaryembodiments, the face 64 ab is at least partially defined by the annularridge 70. Further still, a fluid bore 72 having a full-bore insidediameter D5 extends longitudinally through the seat element 64 a,including the opposing faces 64 aa and 64 ab, thus defining an interiorsurface 74 in the seat element 64 a. Finally, an annular recess 76having an inside diameter D6 is formed in the interior surface 74. Theinside diameter D6 is greater than the full-bore inside diameter D5. Thefull-bore inside diameter D5 is a “full-bore inside diameter” because itis unimpeded along the interior surface 74, as shown in FIG. 3. Theannular recess 76 defines an interior surface 78 and an annular shoulder80 in the seat element 64 a. The annular shoulder 80 adjoins theinterior surface 74 of the seat element 64 a. Moreover, the interiorsurface 78 adjoins both the annular shoulder 80 and the face 64 aa ofthe seat element 64 a. The face 64 aa of the seat element 64 a isadapted to abut, or nearly abut, the annular shoulder 40 in the valvebody 12 when the seat element 64 a is installed in the valve body 12, aswill be discussed in further detail below.

The seat element 64 b includes an annular groove 82 a formed in the face64 ba thereof. The annular groove 82 a is adapted to accommodate anannular seal 82 b. Further, an annular ridge 84 extends radially outwardfrom the exterior of the seat element 64 b. In several exemplaryembodiments, the face 64 bb is at least partially defined by the annularridge 84. Further still, a fluid bore 86 having a full-bore insidediameter D7 extends longitudinally through the seat element 64 b,including the opposing faces 64 ba and 64 bb, thus defining an interiorsurface 88 in the seat element 64 b. Finally, an annular recess 90having an inside diameter D8 is formed in the interior surface 88. Theinside diameter D8 is greater than the full-bore inside diameter D7. Thefull-bore inside diameter D7 is a “full-bore inside diameter” because itis unimpeded along the interior surface 88, as shown in FIG. 3. Theannular recess 90 defines an interior surface 92 and an annular shoulder94 in the seat element 64 b. The annular shoulder 94 adjoins theinterior surface 88 of the seat element 64 b. Moreover, the interiorsurface 92 adjoins both the annular shoulder 94 and the face 64 ba ofthe seat element 64 b. The face 64 ba of the seat element 64 b isadapted to abut, or nearly abut, the annular shoulder 58 in the valvebody 12 when the seat element 64 b is installed in the valve body 12, aswill be discussed in further detail below. In several exemplaryembodiments, the full-bore inside diameters D5 and D7 are equal. Inseveral exemplary embodiments, the inside diameters D6 and D8 are equal.In several exemplary embodiments, the inside diameters D5 and D6 areequal to the inside diameters D7 and D8, respectively.

The protective sleeves 65 a and 65 b are generally cylindrical tubesadapted to protect the annular seals 68 b and 82 b, from blowout,wear-out, and/or deterioration, as will be discussed in further detailbelow. In several exemplary embodiments, the protective sleeves 65 a and65 b are substantially identical to one another.

When the seat element 64 a is installed in the valve body 12, theprotective sleeve 65 a is adapted to extend within the respectiveannular recesses 36 and 76 of the valve body 12 and the seat element 64a. The protective sleeve 65 a extends between respective portions of thevalve body 12 and the seat element 64 a, that is, between the annularshoulder 44 and the annular shoulder 80. As a result, in severalexemplary embodiments, an interior surface 65 aa of the protectivesleeve 65 a is adapted to be substantially aligned, or substantiallyflush, with the respective interior surfaces 32 and 74 of the valve body12 and the seat element 64 a. Moreover, the protective sleeve 65 a has afull-bore inside diameter D9. The full-bore inside diameter D9 is a“full-bore inside diameter” because it is unimpeded along the interiorsurface 65 aa, as shown in FIG. 3. In several exemplary embodiments, thefull-bore inside diameter D9 is equal to the full-bore inside diameterD1 of the fluid bore 28.

Similarly, when the seat element 64 b is installed in the valve body 12,the protective sleeve 65 b is adapted to extend within the respectiveannular recesses 54 and 90 of the valve body 12 and the seat element 64b. The protective sleeve 65 b extends between respective portions of thevalve body 12 and the seat element 64 b, that is, between the annularshoulder 62 and the annular shoulder 94. As a result, in severalexemplary embodiments, an interior surface 65 ba of the protectivesleeve 65 b is adapted to be substantially aligned, or substantiallyflush, with the respective interior surfaces 50 and 88 of the valve body12 and the seat element 64 b. Moreover, the protective sleeve 65 b has afull-bore inside diameter D10. The full-bore inside diameter D10 is a“full-bore inside diameter” because it is unimpeded along the interiorsurface 65 ba, as shown in FIG. 3. In several exemplary embodiments, thefull-bore inside diameter D10 is equal to the full-bore inside diameterD3 of the fluid bore 46. In several exemplary embodiments, the full-boreinside diameters D9 and D10 are equal.

In several exemplary embodiments, each of the protective sleeves 65 aand 65 b is composed of hardenable steel. In several exemplaryembodiments, each of the protective sleeves 65 a and 65 b is composed ofa 4000 Series Steel. In several exemplary embodiments, each of theprotective sleeves 65 a and 65 b is composed of 8620 Steel. In severalexemplary embodiments, each of the protective sleeves 65 a and 65 b iscomposed of carburized steel.

The gate guide 66 a is adapted to circumscribe the exterior of the seatelement 64 a and to be supported, for example, in a substantiallyparallel relation to the gate guide 66 b. In several exemplaryembodiments, the gate guide 66 a is adapted to circumscribe the annularridge 70 of the seat element 64 a. In several exemplary embodiments,when the gate guide 66 a circumscribes the seat element 64 a, at least aportion of the gate guide 66 a is substantially co-planar with the face64 ab of the seat element 64 a.

The gate guide 66 b is adapted to circumscribe the exterior of the seatelement 64 b and to be supported, for example, in a substantiallyparallel relation to the gate guide 66 a. In several exemplaryembodiments, the gate guide 66 b is adapted to circumscribe the annularridge 84 of the seat element 64 b. In several exemplary embodiments,when the gate guide 66 b circumscribes the seat element 64 b, at least aportion of the gate guide 66 b is substantially co-planar with the face64 bb of the seat element 64 a.

In several exemplary embodiments, the gate guides 66 a and 66 b aresubstantially identical to one another. In several exemplaryembodiments, the gate guides 66 a and 66 b are connected to one another.In several exemplary embodiments, the gate guides 66 a and 66 b areintegrally formed. In several exemplary embodiments, the gate guides 66a and 66 b together define a tubular member.

Referring to FIG. 4, with continuing reference to FIGS. 1A and 1B, anexemplary embodiment of the gate assembly 16 is illustrated. The gateassembly 16 includes a gate, such as, for example, a slab 96; anoperating stem 98 adapted to be connected to the slab 96; and a balancestem 100 adapted to be connected to the slab 96 opposite the operatingstem 98. The slab 96 defines opposing end portions 96 a and 96 b. Ablock portion 102 is defined in the end portion 96 a of the slab 96. Inseveral exemplary embodiments, the block portion 102 forms a solid massthat is free of any holes, gaps, cavities, openings, apertures, voids,or the like. In contrast, a fluid bore 104 extends through the endportion 96 b of the slab 96 along a longitudinal center axis 106. Thefluid bore 104 has a full-bore inside diameter D11 and defines aninterior surface 108 in the slab 96. The full-bore inside diameter D11is a “full-bore inside diameter” because it is unimpeded along theinterior surface 108, as shown in FIG. 4. When the valve seat 14 and thegate assembly 16 are installed in the valve body 12, the slab 96 isadapted to be constrained on one side by the seat element 64 a and thegate guide 66 a and, on the other side, by the seat element 64 b and thegate guide 66 b. Constrained as such, the slab 96 is adapted to moveaxially between the open configuration and the closed configuration, aswill be described in further detail below.

The operating stem 98 and the balance stem 100 are connected to the endportions 96 a and 96 b, respectively, of the slab 96, via a pair of gatenuts 110 a and 110 b, respectively. In several exemplary embodiments,when the operating stem 98 and the balance stem 100 are connected to theslab 96, the operating stem 98 and the balance stem 100 are adapted tobe substantially co-axial. Moreover, in several exemplary embodiments,the operating stem 98 and the balance stem 100 are adapted to besubstantially co-axial with the longitudinal center axis 24 of the valvebody 12 when the gate assembly 16 is installed in the valve body 12.

Referring to FIG. 5, with continuing reference to FIGS. 1A and 1B, anexemplary embodiment of the operating end 18 is illustrated. Theoperating end 18 includes a bonnet 112 and a linear actuator such as,for example, a ballscrew assembly 114 connected to the bonnet 112. Thebonnet 112 is adapted to be connected to the valve body 12 via, forexample, a plurality of fasteners 122 (shown in FIG. 7). An internalpassage 116 extends longitudinally through the bonnet 112. The internalpassage 116 defines an enlarged inside diameter portion 116 a and areduced inside diameter portion 116 b. In several exemplary embodiments,the internal passage 116 of the bonnet 112 is adapted to besubstantially co-axial with the longitudinal center axis 24 of the valvebody 12 when the bonnet 112 is connected to the valve body 12.

The enlarged inside diameter portion 116 a of the internal passage 116is adapted to accommodate the gate nut 110 a of the operating stem 98when the gate assembly 16 is in the open configuration. A seal gland 118is defined in the reduced inside diameter portion 116 b of the internalpassage 116. The seal gland 118 accommodates a packing element 120,which packing element, in turn, is adapted to provide both a static anda dynamic seal between the bonnet 112 and the operating stem 98 of thegate assembly 16. A balancing port (not shown) may be formed through thebonnet 112 into the internal passage 116. During operation, as will bediscussed in further detail below, the balancing port may be placed incommunication with the fluid exiting the fluid bore 46 of the gate valve10. Such fluid communication facilitates the balancing of axial forcessuch as, for example, hydraulic lift forces, which are exerted on thegate assembly 16.

The ballscrew assembly 114 includes a ballscrew housing 124, a ballscrew126 extending within the ballscrew housing 124, and a ballscrew nut 128that threadably engages the ballscrew 126. The ballscrew housing 124defines opposing end portions 124 a and 124 b. The end portion 124 b ofthe ballscrew housing 124 is connected to the bonnet 112. An internalpassage 130 extends longitudinally through the ballscrew housing 124. Inseveral exemplary embodiments, when the operating end 18 is connected tothe valve body 12, the internal passage 130 is substantially co-axialwith the longitudinal center axis 24 of the valve body 12.

The ballscrew nut 128 is held at opposite ends by an upper bearingspacer 132 and an adapter stem 134. The upper bearing spacer 132 issupported within the ballscrew housing 124 by a lower thrust bearing 136and a lower bearing spacer 138, which together permit the upper bearingspacer 132 to rotate within the ballscrew housing 124. Similarly, theadapter stem 134 is supported within the ballscrew housing 124 by aradial bearing 140 and an outer thrust bearing 142, which togetherpermit the adapter stem 134 to rotate within the ballscrew housing 124.Accordingly, the adapter stem 134, the ballscrew nut 128, and the upperbearing spacer 132 are together capable of rotating within the ballscrewhousing 124 and relative to the ballscrew 126. A cover plate 144 isconnected at the end portion 124 a of the ballscrew housing 124 toaccommodate a portion of the adapter stem 134. A handle 146 is connectedto a portion of the adapter stem 134 extending outside the ballscrewhousing 124.

The handle 146 is adapted to rotate the adapter stem 134, the ballscrewnut 128, and the upper bearing spacer 132 in relation to the ballscrew126, thus displacing the ballscrew 126 axially in relation to theballscrew nut 128. Moreover, when the bonnet 112 is connected to thevalve body 12, the ballscrew 126 is adapted to be connected to theoperating stem 98 of the gate assembly 16 so that any axial displacementof the ballscrew 126 is transmitted to the operating stem 98. As aresult, rotation of the handle 146 actuates the gate assembly 16 betweenthe open configuration and the closed configuration, as will bediscussed in further detail below.

Referring to FIG. 6, with continuing reference to FIGS. 1A and 1B, anexemplary embodiment of the balancing end 20 is illustrated. Thebalancing end 20 includes a bonnet 148 and a stem protector 150connected to the bonnet 148. The bonnet 148 is adapted to be connectedto the valve body 12, opposite the bonnet 112, via, for example, aplurality of fasteners 158 (shown in FIG. 7). An internal passage 152extends longitudinally through the bonnet 148. The internal passage 152defines an enlarged inside diameter portion 152 a and a reduced insidediameter portion 152 b. In several exemplary embodiments, the internalpassage 152 of the bonnet 148 is adapted to be substantially co-axialwith the longitudinal center axis 24 of the valve body 12 when thebonnet 148 is connected to the valve body 12.

The enlarged inside diameter portion 152 a of the internal passage 152is adapted to accommodate the gate nut 110 b of the balance stem 100when the gate assembly 16 is in the closed configuration. A seal gland154 is defined in the reduced inside diameter portion 152 b of theinternal passage 152. The seal gland 154 accommodates a packing element156, which packing element, in turn, is adapted to provide both a staticand a dynamic seal between the bonnet 148 and the balance stem 100 ofthe gate assembly 16. A balancing port (not shown) may be formed throughthe bonnet 148 into the internal passage 152. During operation, as willbe discussed in further detail below, the balancing port may be placedin communication with the fluid exiting the fluid bore 46 of the gatevalve 10. Such fluid communication facilitates the balancing of axialforces such as, for example, hydraulic lift, exerted on the gateassembly 16.

The stem protector 150 defines opposing end portions 150 a and 150 b.The end portion 150 a of the stem protector 150 is connected to thebonnet 148. An internal cavity 160 is defined in the stem protector 150and is adapted to accommodate the balance stem 100 when the gateassembly 16 is in the closed configuration. In several exemplaryembodiments, when the balancing end 20 is connected to the valve body12, the internal cavity 160 is substantially co-axial with thelongitudinal center axis 24 of the valve body 12. An end cap 162 isformed at the end portion 150 b of the stem protector 150.

Referring to FIG. 7, the gate valve 10 is illustrated in an assembledcondition, including the valve body 12, the valve seat 14, the gateassembly 16, the operating end 18, and the balancing end 20.

In the assembled condition, the seat elements 64 a and 64 b of the valveseat 14 extend within the respective annular recesses 34 and 52 of thevalve body 12. As a result, the protective sleeve 65 a extends withinthe respective annular recesses 36 and 76 of the valve body 12 and theseat element 64 a. Moreover, the protective sleeve 65 b extends withinthe respective annular recesses 54 and 90 of the valve body 12 and theseat element 64 b. In this position, the gate guides 66 a and 66 b aresupported by the seat elements 64 a and 64 b in, for example, asubstantially parallel relation.

Further, the slab 96 is constrained on one side by the seat element 64 aand the gate guide 66 a and, on the other side, by the seat element 64 band the gate guide 66 b. In this position, the slab 96 is adapted tomove axially between the open and closed configurations. The operatingstem 98 and the balance stem 100 are connected to the slab 96 via thegate nuts 110 a and 110 b, respectively. In several exemplaryembodiments, the operating stem 98 and the balance stem 100 aresubstantially co-axial with the longitudinal center axis 24 of the valvebody 12.

Further still, the bonnet 112 is connected to the valve body 12 via, forexample, the plurality of fasteners 122. The end portion 124 b of theballscrew housing 124 is connected to the bonnet 112. In severalexemplary embodiments, the internal passage 116 of the bonnet 112 andthe internal passage 130 of the ballscrew housing 124 are substantiallyco-axial with the longitudinal center axis 24 of the valve body 12. Theoperating stem 98 of the gate assembly 16 extends within the internalpassage 116 of the bonnet 112 so that the packing element 120 providesstatic and dynamic sealing between the bonnet 112 and the operating stem98. Moreover, the operating stem 98 is connected to the ballscrew 126 sothat any rotation of the ballscrew nut 128 axially displaces both theballscrew 126 and the operating stem 98.

Finally, the bonnet 148 is connected to the valve body 12, opposite thebonnet 112, via, for example, the plurality of fasteners 158. The endportion 150 a of the stem protector 150 is connected to the bonnet 148.In several exemplary embodiments, the internal passage 152 of the bonnet148 and the internal cavity 160 of the stem protector 150 aresubstantially co-axial with the longitudinal center axis 24 of the valvebody 12. The balance stem 100 of the gate assembly 16 extends within theinternal passage 152 of the bonnet 148 so that the packing element 156provides static and dynamic sealing between the bonnet 148 and thebalance stem 100.

Referring now to FIGS. 8A and 8B, with continuing reference to FIG. 7,an enlarged view of a portion of the assembled gate valve 10 isillustrated. The face 64 aa of the seat element 64 a abuts, or nearlyabuts, the annular shoulder 40 of the valve body 12. As a result, theinterior surface 78 of the seat element 64 a is substantially alignedwith the interior surface 42 of the valve body 12. In several exemplaryembodiments, the inside diameter D2 of the annular recess 36 in thevalve body 12 is substantially equal as the inside diameter D4 of theannular recess 76 in the seat element 64 a. The annular groove 68 a ofthe seat element 64 a accommodates the annular seal 68 b, whichsealingly engages the annular shoulder 40 of the valve body 12. Theannular seal 68 b extends between and engages the valve body 12 and theseat element 64 a.

Similarly, the face 64 ba of the seat element 64 b abuts, or nearlyabuts, the annular shoulder 58 of the valve body 12. As a result, theinterior surface 92 of the seat element 64 b is substantially alignedwith the interior surface 60 of the valve body 12. In several exemplaryembodiments, the inside diameter D4 of the annular recess 54 in thevalve body 12 is substantially equal as the inside diameter D8 of theannular recess 90 in the seat element 64 b. The annular groove 82 a ofthe seat element 64 b accommodates the annular seal 82 b, whichsealingly engages the annular shoulder 58 of the valve body 12. Theannular seal 82 b extends between and engages the valve body 12 and theseat element 64 b.

The protective sleeve 65 a extends within the respective annularrecesses 36 and 76 of the valve body 12 and the seat element 64 a.Specifically, the protective sleeve 65 a engages the interior surface 42and engages, or nearly engages, the annular shoulder 44 of the valvebody 12. Moreover, the protective sleeve 65 a engages the interiorsurface 78 and engages, or nearly engages, the annular shoulder 80 ofthe seat element 64 a. As a result, the interior surface 65 aa of theprotective sleeve 65 a is substantially aligned with the respectiveinterior surfaces 32 and 74 of the valve body 12 and the seat element 64a. In this position, the protective sleeve 65 a is adapted to protectthe annular seal 68 b from blowout, wear-out, and/or deterioration.

In several exemplary embodiments, the full-bore inside diameter D1 ofthe fluid bore 28 in the valve body 12, the full-bore inside diameter D5of the fluid bore 72 in the seat element 64 a, and the full-bore insidediameter D9 of the protective sleeve 65 a, are substantially equal. Inseveral exemplary embodiments, the protective sleeve 65 a does notobstruct the full-bore inside diameter D1 of the fluid bore 28 in thevalve body 12 or the full-bore inside diameter D5 of the fluid bore 72in the seat element 64 a.

In several exemplary embodiments, the protective sleeve 65 a covers theannular seal 68 b and is substantially centered on the interface betweenthe face 64 aa of the seat element 64 a and the annular shoulder 40 ofthe valve body 12. In several exemplary embodiments, at least a 50%proportion of the protective sleeve 65 a extends on each of the opposingsides of the interface between the face 64 aa and the annular shoulder40. In several exemplary embodiments, a smaller proportion of theprotective sleeve 65 a extends on one of the opposing sides of theinterface between the face 64 aa and the annular shoulder 40, such as,for example, 49%, 48%, 47%, 46%, 45%, 40%, 35%, 30%, 25%, 20%, or 10%.As a result, in several exemplary embodiments, a larger proportion ofthe protective sleeve 65 a extends on the other of the opposing sides ofthe interface between the face 64 aa and the annular shoulder 40, suchas, for example, 51%, 52%, 53%, 54%, 55%, 60%, 65%, 70%, 75%, 80% or90%, respectively.

The protective sleeve 65 b extends within the respective annularrecesses 54 and 90 of the valve body 12 and the seat element 64 b.Specifically, the protective sleeve 65 b engages the interior surface 60and engages, or nearly engages, the annular shoulder 62 of the valvebody 12. Moreover, the protective sleeve 65 b engages the interiorsurface 92 and engages, or nearly engages, the annular shoulder 94 ofthe seat element 64 b. As a result, the interior surface 65 ba of theprotective sleeve 65 b is substantially aligned with the respectiveinterior surfaces 50 and 88 of the valve body 12 and the seat element 64b. In this position, the protective sleeve 65 b is adapted to protectthe annular seal 82 b from blowout, wear-out, and/or deterioration.

In several exemplary embodiments, the full-bore inside diameter D3 ofthe fluid bore 46 in the valve body 12, the full-bore inside diameter D7of the fluid bore 86 in the seat element 64 b, and the full-bore insidediameter D10 of the protective sleeve 65 a, are substantially equal. Inseveral exemplary embodiments, the protective sleeve 65 b does notobstruct the full-bore inside diameter D7 of the fluid bore 46 in thevalve body 12 or the full-bore inside diameter D7 of the fluid bore 86in the seat element 64 a.

In several exemplary embodiments, the protective sleeve 65 b covers theannular seal 82 b and is substantially centered on the interface betweenthe face 64 ba of the seat element 64 b and the annular shoulder 58 ofthe valve body 12. In several exemplary embodiments, at least a 50%proportion of the protective sleeve 65 b extends on each of the opposingsides of the interface between the face 64 ba and the annular shoulder58. In several exemplary embodiments, a smaller proportion of theprotective sleeve 65 b extends on one of the opposing sides of theinterface between the face 64 ba and the annular shoulder 58, such as,for example, 49%, 48%, 47%, 46%, 45%, 40%, 35%, 30%, 25%, 20%, or 10%.As a result, in several exemplary embodiments, a larger proportion ofthe protective sleeve 65 b extends on the other of the opposing sides ofthe interface between the face 64 ba and the annular shoulder 58, suchas, for example, 51%, 52%, 53%, 54%, 55%, 60%, 65%, 70%, 75%, 80% or90%, respectively.

In operation, in an exemplary embodiment, as illustrated in FIGS. 8A and8B with continuing reference to FIGS. 1A-7, the gate valve 10 isactuable between the open configuration and the closed configuration.The gate valve 10 is actuated by using the handle 146 to rotate theadapter stem 134, the ballscrew nut 128, and the upper bearing spacer132 relative to the ballscrew 126. The rotation of the ballscrew nut 128displaces the ballscrew 126 and the gate assembly 16 axially in relationto the valve body 12 and the valve seat 14. The axial displacement ofgate assembly 16 causes the slab 96 to slidably engage the valve seat14. Specifically, one side of the slab 96 engages the seat element 64 aand the gate guide 66 a and the other side of the slab 96 engages theseat element 64 b and the gate guide 66 b, thus actuating the gate valve10 between the open configuration and the closed configuration.

In several exemplary embodiments, in operation, the gate valve 10 ispart of a fluid system through which fluid flows. In several exemplaryembodiments, in operation, the gate valve 10 is part of a “frac stack”used in hydraulic fracturing operations, with fluid flowing through thefrac stack, including the gate valve 10, before, during, and/or afterhydraulic fracturing operations. In several exemplary embodiments, inoperation, the gate valve 10 is a “frac valve.”

In the open configuration, as shown in FIG. 8A, a fluid 164 iscommunicated, or flows, between the fluid bores 28 and 46 of the valvebody 12 via the fluid bore 104 of the slab 96, the respective fluidbores 72 and 86 of the seat elements 64 a and 64 b, and the protectivesleeves 65 a and 65 b. In several exemplary embodiments, the fluid 164includes liquid materials and solid materials. In several exemplaryembodiments, the fluid 164 is, or includes, a slurry that includesliquid materials and solid materials. In several exemplary embodiments,the fluid 164 is a multiphase flow that includes liquid materials, solidmaterials, and gas materials.

During the flow of the fluid 164 between the fluid bores 28 and 46 ofthe valve body 12 via the fluid bore 104 of the slab 96, the respectivefluid bores 72 and 86 of the seat elements 64 a and 64 b, and theprotective sleeves 65 a and 65 b, the interior surface 108 of the slab96 is substantially aligned with the interior surfaces 74 and 88 of theseat elements 64 a and 64 b, thus preventing, or at least limiting,increased turbulence in the flow of the fluid 164 and resultant wear tothe components of the gate valve 10. The enlarged inside diameterportion 116 a of the bonnet 112 accommodates the gate nut 110 a of theoperating stem 98 when the gate assembly 16 is in the openconfiguration.

Further, the annular seal 68 b prevents, or at least reduces, leakage ofthe fluid 164, along the interface between the seat element 64 a and thevalve body 12, into the internal region 22. The protective sleeve 65 aprotects the annular seal 68 b from blowout, wear-out, and/ordeterioration from the fluid 164. Moreover, the substantial alignment ofthe interior surface 65 aa of the protective sleeve 65 a with theinterior surface 32 of the valve body 12 and the interior surface 74 ofthe seat element 64 a reduces turbulence in the flow of the fluid 164and resultant wear to the components of the gate valve 10.

Further still, the annular seal 82 b prevents, or at least reduces,leakage of the fluid 164, along the interface between the seat element64 a and the valve body 12, into the internal region 22. The protectivesleeve 65 b protects the annular seal 82 b from blowout, wear-out,and/or deterioration from the fluid 164. Moreover, the substantialalignment of the interior surface 65 ba of the protective sleeve 65 bwith the interior surface 50 of the valve body 12 and the interiorsurface 88 of the seat element 64 b reduces turbulence in the flow ofthe fluid 164 and resultant wear to the components of the gate valve 10.

Finally, the flow of the fluid 164 imparts axial forces, such as, forexample, hydraulic lift to the slab 96 during operation of the gatevalve 10. Such axial forces tend to cause misalignment between theinterior surface 108 of the slab 96 and the interior surfaces 74 and 88of the seat elements 64 a and 64 b, respectively. The pressure of thefluid 164 exiting the fluid bore 46 of the valve body 12 may becommunicated to the balancing ports (not shown) in the bonnet 112 andthe bonnet 148; such fluid communication facilitates the balancing ofaxial forces exerted on the gate assembly 16 by the fluid 164 duringoperation of the gate valve 10.

In the closed configuration, as shown in FIG. 8B, the slab 96 isdisplaced by the ballscrew assembly 114 so that the block portion 102 ofthe slab 96 prevents, or at least obstructs, communication of the fluid164 between the fluid bores 28 and 46, respectively, of the valve body12. Specifically, the handle 146 rotates the adapter stem 134, theballscrew nut 128, and the upper bearing spacer 132 in relation to theballscrew 126, thus displacing the ballscrew 126 and, consequently, thegate assembly 16 axially in relation to the ballscrew nut 128. Once theslab 96 has been sufficiently displaced by the ballscrew assembly 114,the interior surface 108 of the slab 96 no longer substantially alignedwith the interior surfaces 74 and 88 of the seat elements 64 a and 64 b,respectively. Instead, the block portion 102 of the slab 96 issubstantially aligned with the interior surfaces 74 and 88 of the seatelements 64 a and 64 b, respectively. The enlarged inside diameterportion 152 a of the bonnet 148 accommodates the gate nut 110 b of thebalance stem 100 when the gate assembly 16 is in the closedconfiguration. Moreover, the annular seal 68 b prevents, or at leastreduces, leakage of the fluid 164, along the interface between the seatelement 64 a and the valve body 12, into the internal region 22. As aresult, the slab 96 prevents, or at least obstructs, communication ofthe fluid 164 between the fluid bores 28 and 46 of the valve body 12.

In several exemplary embodiments, the protective sleeve 65 a does notobstruct either the full-bore inside diameter D1 of the fluid bore 28 inthe valve body 12 or the full-bore inside diameter D5 of the fluid bore72 in the seat element 64 a. In several exemplary embodiments, theprotective sleeve 65 b does not obstruct either the full-bore insidediameter D3 of the fluid bore 46 of the valve body 12 or the full-boreinside diameter D7 of the fluid bore 86 of the seat element 64 b. Inseveral exemplary embodiments, even with the extreme pressures,temperatures, and flow rates encountered by the gate valve 10 duringoperation, the protective sleeves 65 a and 65 b cover and protect theannular seals 68 b and 82 b, respectively, from blowout, wear-out,and/or deterioration by the fluid 164.

In several exemplary embodiments, the wear, erosion, and/or completewash-out of the protective sleeve 65 a is prevented, or at leastreduced, as a result of the substantial alignment between the interiorsurface 32 of the valve body 12, the interior surface 74 of the seatelement 64 a, and the interior surface 65 aa of the protective sleeve 65a. In several exemplary embodiments, the wear, erosion, and/or completewash-out of the protective sleeve 65 b is prevented, or at leastreduced, as a result of the substantial alignment between the interiorsurface 50 of the valve body 12, the interior surface 88 of the seatelement 64 b, and the interior surface 65 ba of the protective sleeve 65b.

In several exemplary embodiments, the wear, erosion, and/or completewash-out of the gate valve 10, including the valve body 12, theprotective sleeve 65 a, and/or the seat element 64 a is prevented, or atleast reduced, as a result of the substantial alignment between theinterior surface 32 of the valve body 12, the interior surface 65 aa ofthe protective sleeve 65 a, and the interior surface 74 of the seatelement 64 a. In several exemplary embodiments, the wear, erosion,and/or complete wash-out of the gate valve 10, including the valve body12, the protective sleeve 65 b, and/or the seat element 64 b isprevented, or at least reduced, as a result of the substantial alignmentbetween the interior surface 50 of the valve body 12, the interiorsurface 65 ba of the protective sleeve 65 b, and the interior surface 88of the seat elements 64 b.

In several exemplary embodiments, as illustrated in FIGS. 1A, 1B, 7, and8A, the full-bore inside diameter D1 of the fluid bore 28, the full-boreinside diameter D9 of the protective sleeve 65 a, the full-bore insidediameter D5 of the seat element 64 a, the full-bore inside diameter D11of the fluid bore 104 of the slab 96, the full-bore inside diameter D7of the seat element 64 b, the full-bore inside diameter D10 of theprotective sleeve 65 b, and the full-bore inside diameter D3 of thefluid bore 46, are all substantially equal; therefore, in operation,when the gate assembly 16 is in the open configuration as shown in FIG.8A, the fluid 164 flows through the gate valve 10 via a substantiallyconstant, full-bore diameter across the gate valve 10, the constant,full-bore diameter equaling the respective full-bore inside diameters D1and D3 of the fluid bores 28 and 46. During this fluid flow, theprotective sleeves 65 a and 65 b protect the annular seals 68 b and 82b, respectively, from the flow of the fluid 164, thereby reducing thelikelihood of blowout, wear-out, and/or deterioration of each of theannular seals 68 b and 82 b. Since the fluid 164 flows through the gatevalve 10 via a substantially constant, full-bore diameter across thegate valve 10, the flow characteristics and/or parameters of the flow ofthe fluid 164 through the gate valve 10 (e.g., fluid flow rate, fluidpressure, degree of turbulence of fluid flow, etc.) are not appreciablyaffected by the inclusion of the protective sleeves 65 a and 65 b.Therefore, the annular seals 68 b and 82 b are protected from blowout,wear-out, and/or deterioration without affecting the flowcharacteristics and/or parameters of the flow of the fluid 164 throughthe gate valve 10.

In an exemplary embodiment, a method of assembling the gate valve 10includes placing the gate valve 10 in the assembled condition describedabove and illustrated in FIG. 7. In an exemplary embodiment, a method ofdisassembling the gate valve 10 includes placing the gate valve 10 in anunassembled condition.

In an exemplary embodiment, a method of retrofitting the gate valve 10includes at least partially disassembling the gate valve 10, removingthe protective sleeve 65 a or 65 b, and reassembling the gate valve 10with a new protective sleeve that is identical to the protective sleeve65 a or 65 b but has never been used, or has been used less than theprotective sleeve 65 a or 65 b. In an exemplary embodiment, a method ofretrofitting the gate valve 10 includes at least partially disassemblingthe gate valve 10, removing the protective sleeves 65 a and 65 b, andreassembling the gate valve 10 with new protective sleeves that areidentical to the protective sleeves 65 a and 65 b but have never beenused, or have been used less than the protective sleeves 65 a and 65 b.In an exemplary embodiment, each of the foregoing retrofitting methodsmay be carried out after the gate valve 10 has completed a predeterminedtime of operation, after a predetermined amount of time has passed sincethe gate valve 10 was first used in the field, after it is determinedthat the protective sleeves 65 a and 65 b have completed theirrespective useful operational lives, or after it is determined that atleast one of the protective sleeves 65 a and 65 b has completed itsuseful operational life. In several exemplary embodiments, the abilityto retrofit the gate valve 10 increases the operational life of the gatevalve 10 as a whole.

In an exemplary embodiment, at least partially disassembling the gatevalve 10 to, for example, retrofit the gate valve 10 in accordance withthe foregoing, includes: disconnecting the operating end 18 from thevalve body 12, disconnecting the balancing end 20 from the valve body12, removing the gate assembly 16 from the valve body 12 to provideaccess to the internal region 22, and removing the valve seat 14 fromthe valve body 12.

The present disclosure introduces a gate valve, the gate valve includinga valve body, defining: an internal region; a first fluid boreintersecting the internal region and defining a first interior surfacein the valve body; and a first annular recess formed in the firstinterior surface and adjoining the internal region; a first seat elementdefining a second fluid bore and extending within the first annularrecess; and a first protective sleeve extending between respectiveportions of the first seat element and the valve body; wherein the firstfluid bore has a first full-bore inside diameter; wherein the secondfluid bore has a second full-bore inside diameter that is substantiallyequal to the first full-bore inside diameter; and wherein the firstprotective sleeve has a third full-bore inside diameter that issubstantially equal to each of the first and second full-bore insidediameters. In an exemplary embodiment, the third full-bore insidediameter of the first protective sleeve is substantially equal to eachof the first and second full-bore inside diameters so that the firstprotective sleeve does not obstruct either the first full-bore insidediameter of the first fluid bore in the valve body or the secondfull-bore inside diameter of the second fluid bore in the first seatelement. In an exemplary embodiment, the second bore and the firstprotective sleeve define second and third interior surfaces,respectively; wherein the first, second, and third interior surfaces aresubstantially aligned; and wherein wear, erosion, and/or completewash-out of the first protective sleeve is prevented, or at leastreduced, as a result of the substantial alignment between the first,second, and third interior surfaces. In an exemplary embodiment, thegate valve includes a first annular seal extending between and engagingthe valve body and the first seat element; wherein the first protectivesleeve is adapted to protect the first annular seal, reducing thelikelihood of blowout, wear-out, and/or deterioration of the firstannular seal. In an exemplary embodiment, the second bore defines asecond interior surface; wherein the first seat element further definesa second annular recess formed in the second interior surface; andwherein the first protective sleeve extends within the second annularrecess. In an exemplary embodiment, the first annular recess defines afirst annular shoulder in the valve body and the first seat elementdefines a first face, the first face abutting, or nearly abutting, thefirst annular shoulder along a first interface; and wherein a proportionof the first protective sleeve extends on one side of the firstinterface so that the remaining proportion of the first protectivesleeve extends on the other side of the first interface. In an exemplaryembodiment, the valve body further defines: a third fluid boreintersecting the internal region and defining a second interior surfacein the valve body; and a second annular recess formed in the secondinterior surface and adjoining the internal region; and wherein the gatevalve further includes: a second seat element defining a fourth fluidbore and extending within the second annular recess; and a secondprotective sleeve extending between respective portions of the secondseat element and the valve body. In an exemplary embodiment, the thirdfluid bore has a fourth full-bore inside diameter, the fourth fluid borehas a fifth full-bore inside diameter, and the second protective sleevehas a sixth full-bore inside diameter; and wherein the first, second,third, fourth, fifth, and sixth full-bore inside diameters aresubstantially equal. In an exemplary embodiment, the first, second,third, fourth, fifth, and sixth full-bore inside diameters aresubstantially equal so that, when a fluid flows through the gate valve,the fluid flows through the gate valve via a substantially constant,full-bore diameter across the gate valve. In an exemplary embodiment,the gate valve includes a first annular seal extending between andengaging the valve body and the first seat element; and a second annularseal extending between and engaging the valve body and the second seatelement; wherein the first and second protective sleeves are adapted toprotect the first and second annular seals, respectively, reducing thelikelihood of blowout, wear-out, and/or deterioration of the first andsecond annular seals. In an exemplary embodiment, the gate valveincludes a gate including a fifth fluid bore; wherein the gate isactuable between: an open configuration, in which a fluid is permittedto flow through the first, second, third, fourth, and fifth fluid bores,and a closed configuration, in which the fluid is restricted fromflowing through the fifth fluid bore. In an exemplary embodiment, thefirst annular recess defines a first annular shoulder in the valve bodyand the first seat element defines a first face, the first faceabutting, or nearly abutting, the first annular shoulder along a firstinterface; and wherein the second annular recess defines a secondannular shoulder in the valve body and the second seat element defines asecond face, the second face abutting, or nearly abutting, the secondannular shoulder along a second interface. In an exemplary embodiment, aproportion of the first protective sleeve extends on one side of thefirst interface so that the remaining proportion of the first protectivesleeve extends on the other side of the first interface; and wherein aproportion of the second protective sleeve extends on one side of thesecond interface so that the remaining proportion of the secondprotective sleeve extends on the other side of the second interface.

The present disclosure also introduces a gate valve that includes avalve body, defining: an internal region; a first fluid boreintersecting the internal region and defining a first interior surfacein the valve body; a first annular recess formed in the first interiorsurface, the first annular recess adjoining the internal region; and asecond annular recess formed in the first interior surface, the secondannular recess adjoining the first annular recess; a first seat elementextending within the first annular recess, the first seat elementdefining: a second fluid bore defining a second interior surface; and athird annular recess formed in the second interior surface; and a firstprotective sleeve extending within the second and third annularrecesses. In an exemplary embodiment, the gate valve includes a firstannular seal extending between and engaging the valve body and the firstseat element; wherein the first protective sleeve is adapted to protectthe first annular seal, reducing the likelihood of blowout, wear-out,and/or deterioration of the first annular seal. In an exemplaryembodiment, the first bore, the second bore, and the first protectivesleeve define first, second, and third interior surfaces, respectively;wherein the first, second, and third interior surfaces are substantiallyaligned; and wherein wear, erosion, and/or complete wash-out of thefirst protective sleeve is prevented, or at least reduced, as a resultof the substantial alignment between the first, second, and thirdinterior surfaces. In an exemplary embodiment, the first fluid bore hasa first full-bore inside diameter, the second fluid bore has a secondfull-bore inside diameter, and the first protective sleeve has a thirdfull-bore inside diameter, the first, second, and third full-bore insidediameters being substantially equal. In an exemplary embodiment, thethird full-bore inside diameter of the first protective sleeve issubstantially equal to each of the first and second full-bore insidediameters so that the first protective sleeve does not obstruct eitherthe first full-bore inside diameter of the first fluid bore in the valvebody or the second full-bore inside diameter of the second fluid bore inthe first seat element. In an exemplary embodiment, the second and thirdannular recesses have fourth and fifth inside diameters, respectively,the fourth and fifth inside diameters being substantially equal. In anexemplary embodiment, the first annular recess defines a first annularshoulder in the valve body and the first seat element defines a firstface, the first face abutting, or nearly abutting, the first annularshoulder along a first interface; and wherein a proportion of the firstprotective sleeve extends on one side of the first interface so that theremaining proportion of the first protective sleeve extends on the otherside of the first interface. In an exemplary embodiment, the valve bodyfurther defines: a third fluid bore intersecting the internal region anddefining a third interior surface in the valve body; a fourth annularrecess formed in the third interior surface, the fourth annular recessadjoining the internal region; and a fifth annular recess formed in thethird interior surface, the fifth annular recess adjoining the fourthannular recess; and wherein the gate valve further includes: a secondseat element extending within the fourth annular recess, the second seatelement defining: a fourth fluid bore defining a fourth interiorsurface; and a sixth annular recess formed in the fourth interiorsurface; and a second protective sleeve extending within the fifth andsixth annular recesses. In an exemplary embodiment, the gate valveincludes a first annular seal extending between and engaging the valvebody and the first seat element; and a second annular seal extendingbetween and engaging the valve body and the second seat element; whereinthe first and second protective sleeves are adapted to protect the firstand second annular seals, respectively, reducing the likelihood ofblowout, wear-out, and/or deterioration of the first and second annularseals. In an exemplary embodiment, the first annular recess defines afirst annular shoulder in the valve body and the first seat elementdefines a first face, the first face abutting, or nearly abutting, thefirst annular shoulder along a first interface; wherein the fourthannular recess defines a second annular shoulder in the valve body andthe second seat element defines a second face, the second face abutting,or nearly abutting, the second annular shoulder along a secondinterface; wherein a proportion of the first protective sleeve extendson one side of the first interface so that the remaining proportion ofthe first protective sleeve extends on the other side of the firstinterface; and wherein a proportion of the second protective sleeveextends on one side of the second interface so that the remainingproportion of the second protective sleeve extends on the other side ofthe second interface. In an exemplary embodiment, the first fluid borehas a first full-bore inside diameter, the second fluid bore has asecond full-bore inside diameter, and the first protective sleeve has athird full-bore inside diameter, the first, second, and third full-boreinside diameters being substantially equal; and wherein the third fluidbore has a fourth full-bore inside diameter, the fourth fluid bore has afifth full-bore inside diameter, and the second protective sleeve has asixth full-bore inside diameter, the fourth, fifth, and sixth full-boreinside diameters being substantially equal. In an exemplary embodiment,the first, second, third, fourth, fifth, and sixth full-bore insidediameters are substantially equal so that, when a fluid flows throughthe gate valve, the fluid flows through the gate valve via asubstantially constant, full-bore diameter across the gate valve. In anexemplary embodiment, the second and third annular recesses have seventhand eighth inside diameters, respectively, the seventh and eighth insidediameters being substantially equal; and wherein the fifth and sixthannular recesses have ninth and tenth inside diameters, respectively,the ninth and tenth inside diameters being substantially equal.

The present disclosure also introduces a gate valve that includes avalve body, defining: an internal region; a first fluid boreintersecting the internal region and defining a first interior surfacein the valve body; and a first annular recess formed in the firstinterior surface and adjoining the internal region, the first annularrecess defining a first annular shoulder in the valve body; a first seatelement defining a second fluid bore and extending within the firstannular recess, the first seat element defining a first face; and afirst protective sleeve extending between respective portions of thefirst seat element and the valve body; wherein the first face abuts, ornearly abuts, the first annular shoulder along a first interface. In anexemplary embodiment, a proportion of the first protective sleeveextends on one side of the first interface so that the remainingproportion of the first protective sleeve extends on the other side ofthe first interface. In an exemplary embodiment, wherein the valve bodyfurther defines: a third fluid bore intersecting the internal region anddefining a second interior surface in the valve body; and a secondannular recess formed in the second interior surface and adjoining theinternal region, the second annular recess defining a second annularshoulder in the valve body; wherein the gate valve further includes: asecond seat element including a fourth fluid bore and extending withinthe second annular recess, the second seat element defining a secondface; and a second protective sleeve extending between respectiveportions of the second seat element and the valve body; and wherein thesecond face abuts, or nearly abuts, the second annular shoulder along asecond interface. In an exemplary embodiment, a proportion of the firstprotective sleeve extends on one side of the first interface so that theremaining proportion of the first protective sleeve extends on the otherside of the first interface; and wherein a proportion of the secondprotective sleeve extends on one side of the second interface so thatthe remaining proportion of the second protective sleeve extends on theother side of the second interface.

The present disclosure also introduces a valve seat adapted to beengaged with a valve body of a gate valve, the valve body having a firstfull-bore diameter, the valve seat including: a first seat elementadapted to extend within a first annular recess of the valve body, thefirst seat element defining: a first fluid bore, the first fluid boredefining a first interior surface; and a first annular recess formed inthe first interior surface, the first annular recess defining a firstface; wherein the first fluid bore has a second full-bore diameter thatis substantially equal to the first full-bore diameter of the valve bodywith which the valve seat is adapted to be engaged. In an exemplaryembodiment, the first seat element defines a first face adapted to abut,or nearly abut, a first annular shoulder of the valve body. In anexemplary embodiment, the valve seat includes a first annular grooveformed in the first face; and a first annular seal extending within thefirst annular groove; wherein the first annular seal is adapted tosealingly engage the first annular shoulder of the valve body. In anexemplary embodiment, the valve seat includes a second seat elementadapted to extend within a second annular recess of the valve body, thesecond seat element defining: a second fluid bore, the second fluid boredefining a second interior surface; and a second annular recess formedin the second interior surface, the second annular recess defining asecond face; wherein the second fluid bore has a third full-borediameter that is substantially equal to each of: the first full-borediameter of the valve body with which the valve seat is adapted to beengaged; and the second full-bore diameter. In an exemplary embodiment,the first seat element defines a first face adapted to abut, or nearlyabut, a first annular shoulder of the valve body; and wherein the secondseat element defines a second face adapted to abut, or nearly abut, asecond annular shoulder of the valve body. In an exemplary embodiment,the valve seat includes first and second annular grooves formed in thefirst and second faces, respectively; and first and second annular sealsextending within the first and second annular grooves, respectively;wherein the first and second annular seals are adapted to sealinglyengage the first and second annular shoulders, respectively, of thevalve body.

The present disclosure also introduces a kit for a gate valve, the kitincluding: a valve body, defining: an internal region; a first fluidbore intersecting the internal region and defining a first interiorsurface in the valve body; and a first annular recess formed in thefirst interior surface and adjoining the internal region; a first seatelement defining a second fluid bore and adapted to extend within thefirst annular recess; and a first protective sleeve adapted to extendbetween respective portions of the first seat element and the valvebody; wherein the first fluid bore has a first full-bore insidediameter; wherein the second fluid bore has a second full-bore insidediameter that is substantially equal to the first full-bore insidediameter; and wherein the first protective sleeve has a third full-boreinside diameter that is substantially equal to each of the first andsecond full-bore inside diameters. In an exemplary embodiment, the thirdfull-bore inside diameter of the first protective sleeve issubstantially equal to each of the first and second full-bore insidediameters so that the first protective sleeve does not obstruct eitherthe first full-bore inside diameter of the first fluid bore in the valvebody or the second full-bore inside diameter of the second fluid bore inthe first seat element. In an exemplary embodiment, the second bore andthe first protective sleeve define second and third interior surfaces,respectively; wherein the first, second, and third interior surfaces areadapted to be substantially aligned; and wherein wear, erosion, and/orcomplete wash-out of the first protective sleeve is prevented, or atleast reduced, as a result of the substantial alignment between thefirst, second, and third interior surfaces. In an exemplary embodiment,the kit includes a first annular seal adapted to extend between andengage the valve body and the first seat element; wherein the firstprotective sleeve is adapted to protect the first annular seal, reducingthe likelihood of blowout, wear-out, and/or deterioration of the firstannular seal. In an exemplary embodiment, the second bore defines asecond interior surface; wherein the first seat element further definesa second annular recess formed in the second interior surface; andwherein the first protective sleeve is adapted to extend within thesecond annular recess. In an exemplary embodiment, the first annularrecess defines a first annular shoulder in the valve body and the firstseat element defines a first face, wherein the first face is adapted toabut, or nearly abut, the first annular shoulder along a firstinterface; and wherein a proportion of the first protective sleeve isadapted to extend on one side of the first interface so that theremaining proportion of the first protective sleeve extends on the otherside of the first interface. In an exemplary embodiment, the valve bodyfurther defines: a third fluid bore intersecting the internal region anddefining a second interior surface in the valve body; and a secondannular recess formed in the second interior surface and adjoining theinternal region; and wherein the gate valve further includes: a secondseat element defining a fourth fluid bore and adapted to extend withinthe second annular recess; and a second protective sleeve extendingbetween respective portions of the second seat element and the valvebody. In an exemplary embodiment, the third fluid bore has a fourthfull-bore inside diameter, the fourth fluid bore has a fifth full-boreinside diameter, and the second protective sleeve has a sixth full-boreinside diameter; and wherein the first, second, third, fourth, fifth,and sixth full-bore inside diameters are substantially equal. In anexemplary embodiment, the first, second, third, fourth, fifth, and sixthfull-bore inside diameters are substantially equal so that, when a fluidflows through the gate valve, the fluid flows through the gate valve viaa substantially constant, full-bore diameter across the gate valve. Inan exemplary embodiment, the kit includes a first annular seal extendingbetween and engaging the valve body and the first seat element; and asecond annular seal extending between and engaging the valve body andthe second seat element; wherein the first and second protective sleevesare adapted to protect the first and second annular seals, respectively,reducing the likelihood of blowout, wear-out, and/or deterioration ofthe first and second annular seals. In an exemplary embodiment, the kitincludes a gate including a fifth fluid bore; wherein the gate isadapted to be actuable between: an open configuration, in which a fluidis permitted to flow through the first, second, third, fourth, and fifthfluid bores, and a closed configuration, in which the fluid isrestricted from flowing through the fifth fluid bore. In an exemplaryembodiment, the first annular recess defines a first annular shoulder inthe valve body and the first seat element defines a first face, thefirst face abutting, or nearly abutting, the first annular shoulderalong a first interface; and wherein the second annular recess defines asecond annular shoulder in the valve body and the second seat elementdefines a second face, the second face abutting, or nearly abutting, thesecond annular shoulder along a second interface. In an exemplaryembodiment, a proportion of the first protective sleeve is adapted toextend on one side of the first interface so that the remainingproportion of the first protective sleeve extends on the other side ofthe first interface; and wherein a proportion of the second protectivesleeve is adapted to extend on one side of the second interface so thatthe remaining proportion of the second protective sleeve extends on theother side of the second interface.

The present disclosure also introduces a kit for a gate valve, the kitincluding a valve body, defining: an internal region; a first fluid boreintersecting the internal region and defining a first interior surfacein the valve body; a first annular recess formed in the first interiorsurface, the first annular recess adjoining the internal region; and asecond annular recess formed in the first interior surface, the secondannular recess adjoining the first annular recess; a first seat elementadapted to extend within the first annular recess, the first seatelement defining: a second fluid bore defining a second interiorsurface; and a third annular recess formed in the second interiorsurface; and a first protective sleeve adapted to extend within thesecond and third annular recesses. In an exemplary embodiment, the kitincludes a first annular seal adapted to extend between and engage thevalve body and the first seat element; wherein the first protectivesleeve is adapted to protect the first annular seal, reducing thelikelihood of blowout, wear-out, and/or deterioration of the firstannular seal. In an exemplary embodiment, the first bore, the secondbore, and the first protective sleeve define first, second, and thirdinterior surfaces, respectively; wherein the first, second, and thirdinterior surfaces are adapted to be substantially aligned; and whereinwear, erosion, and/or complete wash-out of the first protective sleeveis prevented, or at least reduced, as a result of the substantialalignment between the first, second, and third interior surfaces. In anexemplary embodiment, the first fluid bore has a first full-bore insidediameter, the second fluid bore has a second full-bore inside diameter,and the first protective sleeve has a third full-bore inside diameter,the first, second, and third full-bore inside diameters beingsubstantially equal. In an exemplary embodiment, the third full-boreinside diameter of the first protective sleeve is substantially equal toeach of the first and second full-bore inside diameters so that thefirst protective sleeve does not obstruct either the first full-boreinside diameter of the first fluid bore in the valve body or the secondfull-bore inside diameter of the second fluid bore in the first seatelement. In an exemplary embodiment, the second and third annularrecesses have fourth and fifth inside diameters, respectively, thefourth and fifth inside diameters being substantially equal. In anexemplary embodiment, the first annular recess defines a first annularshoulder in the valve body and the first seat element defines a firstface, the first face abutting, or nearly abutting, the first annularshoulder along a first interface; and wherein a proportion of the firstprotective sleeve is adapted to extend on one side of the firstinterface so that the remaining proportion of the first protectivesleeve extends on the other side of the first interface. In an exemplaryembodiment, the valve body further defines: a third fluid boreintersecting the internal region and defining a third interior surfacein the valve body; a fourth annular recess formed in the third interiorsurface, the fourth annular recess adjoining the internal region; and afifth annular recess formed in the third interior surface, the fifthannular recess adjoining the fourth annular recess; and wherein the gatevalve further includes: a second seat element adapted to extend withinthe fourth annular recess, the second seat element defining: a fourthfluid bore defining a fourth interior surface; and a sixth annularrecess formed in the fourth interior surface; and a second protectivesleeve adapted to extend within the fifth and sixth annular recesses. Inan exemplary embodiment, the kit includes a first annular seal adaptedto extend between and engage the valve body and the first seat element;and a second annular seal adapted to extend between and engage the valvebody and the second seat element; wherein the first and secondprotective sleeves are adapted to protect the first and second annularseals, respectively, reducing the likelihood of blowout, wear-out,and/or deterioration of the first and second annular seals. In anexemplary embodiment, the first annular recess defines a first annularshoulder in the valve body and the first seat element defines a firstface, the first face being adapted to abut, or nearly abut, the firstannular shoulder along a first interface; wherein the fourth annularrecess defines a second annular shoulder in the valve body and thesecond seat element defines a second face, the second face being adaptedto abut, or nearly abut, the second annular shoulder along a secondinterface; wherein a proportion of the first protective sleeve isadapted to extend on one side of the first interface so that theremaining proportion of the first protective sleeve extends on the otherside of the first interface; and wherein a proportion of the secondprotective sleeve is adapted to extend on one side of the secondinterface so that the remaining proportion of the second protectivesleeve extends on the other side of the second interface. In anexemplary embodiment, the first fluid bore has a first full-bore insidediameter, the second fluid bore has a second full-bore inside diameter,and the first protective sleeve has a third full-bore inside diameter,the first, second, and third full-bore inside diameters beingsubstantially equal; and wherein the third fluid bore has a fourthfull-bore inside diameter, the fourth fluid bore has a fifth full-boreinside diameter, and the second protective sleeve has a sixth full-boreinside diameter, the fourth, fifth, and sixth full-bore inside diametersbeing substantially equal. In an exemplary embodiment, the first,second, third, fourth, fifth, and sixth full-bore inside diameters aresubstantially equal so that, when a fluid flows through the gate valve,the fluid flows through the gate valve via a substantially constant,full-bore diameter across the gate valve. In an exemplary embodiment,the second and third annular recesses have seventh and eighth insidediameters, respectively, the seventh and eighth inside diameters beingsubstantially equal; and wherein the fifth and sixth annular recesseshave ninth and tenth inside diameters, respectively, the ninth and tenthinside diameters being substantially equal.

The present disclosure also introduces a kit for a gate valve, the kitincluding: a valve body, defining: an internal region; a first fluidbore intersecting the internal region and defining a first interiorsurface in the valve body; and a first annular recess formed in thefirst interior surface and adjoining the internal region, the firstannular recess defining a first annular shoulder in the valve body; afirst seat element defining a second fluid bore and adapted to extendwithin the first annular recess, the first seat element defining a firstface; and a first protective sleeve adapted to extend between respectiveportions of the first seat element and the valve body; wherein the firstface is adapted to abut, or nearly abut, the first annular shoulderalong a first interface. In an exemplary embodiment, a proportion of thefirst protective sleeve is adapted to extend on one side of the firstinterface so that the remaining proportion of the first protectivesleeve extends on the other side of the first interface. In an exemplaryembodiment, the valve body further defines: a third fluid boreintersecting the internal region and defining a second interior surfacein the valve body; and a second annular recess formed in the secondinterior surface and adjoining the internal region, the second annularrecess defining a second annular shoulder in the valve body; wherein thegate valve further includes: a second seat element including a fourthfluid bore and adapted to extend within the second annular recess, thesecond seat element defining a second face; and a second protectivesleeve adapted to extend between respective portions of the second seatelement and the valve body; and wherein the second face is adapted toabut, or nearly abut, the second annular shoulder along a secondinterface. In an exemplary embodiment, a proportion of the firstprotective sleeve is adapted to extend on one side of the firstinterface so that the remaining proportion of the first protectivesleeve extends on the other side of the first interface; and wherein aproportion of the second protective sleeve is adapted to extend on oneside of the second interface so that the remaining proportion of thesecond protective sleeve extends on the other side of the secondinterface.

The present disclosure also introduces one or more methods according toone or more aspects of the present disclosure.

It is understood that variations may be made in the foregoing withoutdeparting from the scope of the present disclosure.

In several exemplary embodiments, the elements and teachings of thevarious illustrative exemplary embodiments may be combined in whole orin part in some or all of the illustrative exemplary embodiments. Inaddition, one or more of the elements and teachings of the variousillustrative exemplary embodiments may be omitted, at least in part,and/or combined, at least in part, with one or more of the otherelements and teachings of the various illustrative embodiments.

Any spatial references, such as, for example, “upper,” “lower,” “above,”“below,” “between,” “bottom,” “vertical,” “horizontal,” “angular,”“upwards,” “downwards,” “side-to-side,” “left-to-right,”“right-to-left,” “top-to-bottom,” “bottom-to-top,” “top,” “bottom,”“bottom-up,” “top-down,” etc., are for the purpose of illustration onlyand do not limit the specific orientation or location of the structuredescribed above.

In several exemplary embodiments, while different steps, processes, andprocedures are described as appearing as distinct acts, one or more ofthe steps, one or more of the processes, and/or one or more of theprocedures may also be performed in different orders, simultaneouslyand/or sequentially. In several exemplary embodiments, the steps,processes, and/or procedures may be merged into one or more steps,processes and/or procedures.

In several exemplary embodiments, one or more of the operational stepsin each embodiment may be omitted. Moreover, in some instances, somefeatures of the present disclosure may be employed without acorresponding use of the other features. Moreover, one or more of theabove-described embodiments and/or variations may be combined in wholeor in part with any one or more of the other above-described embodimentsand/or variations.

Although several exemplary embodiments have been described in detailabove, the embodiments described are exemplary only and are notlimiting, and those skilled in the art will readily appreciate that manyother modifications, changes and/or substitutions are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of the present disclosure. Accordingly, allsuch modifications, changes, and/or substitutions are intended to beincluded within the scope of this disclosure as defined in the followingclaims. In the claims, any means-plus-function clauses are intended tocover the structures described herein as performing the recited functionand not only structural equivalents, but also equivalent structures.Moreover, it is the express intention of the applicant not to invoke 35U.S.C. § 112, paragraph 6 for any limitations of any of the claimsherein, except for those in which the claim expressly uses the word“means” together with an associated function.

What is claimed is:
 1. A gate valve, comprising: a valve body comprisinga passage formed therein along a first longitudinal center axis, thepassage defining an internal region in the valve body, the internalregion defining a first interior surface in the valve body, the firstinterior surface extending about the first longitudinal center axis;wherein the valve body further comprises a first fluid bore formedtherein along a second longitudinal center axis, the first fluid boreintersecting the internal region and defining a second interior surfacein the valve body; wherein the valve body further comprises: a firstannular recess defining a third interior surface in the valve body, thethird interior surface extending circumferentially about the secondlongitudinal center axis and adjoining the first interior surface; afirst annular shoulder defined in the valve body outside of the internalregion and located between: the first interior surface defined in thevalve body by the internal region; and the second interior surfacedefined in the valve body by the first fluid bore; and a second annularshoulder defined in the valve body outside of the internal region andlocated between: the first annular shoulder; and the second interiorsurface defined in the valve body by the first fluid bore; wherein thegate valve further comprises: a first seat element extending within thefirst annular recess and the internal region, the first seat elementcomprising a second fluid bore defining a fourth interior surface in theseat element; and a first protective sleeve extending on opposing sidesof the first annular shoulder; wherein the first seat element abuts thevalve body; wherein the first fluid bore of the valve body has a firstfull-bore inside diameter, the second fluid bore of the first seatelement has a second full-bore inside diameter, and the first protectivesleeve has a third full-bore inside diameter, the first, second, andthird full-bore inside diameters being substantially equal; and whereinthe first protective sleeve defines an insidecircumferentially-extending surface and an outsidecircumferentially-extending surface radially spaced from the insidecircumferentially-extending surface.
 2. The gate valve of claim 1,wherein the first protective sleeve is devoid of any openings extendingradially therethrough from the outside circumferentially-extendingsurface to the inside circumferentially-extending surface.
 3. The gatevalve of claim 1, wherein the first seat element abuts the first annularshoulder of the valve body.
 4. The gate valve of claim 1, wherein thevalve body further comprises a second annular recess adjoining the firstannular recess; wherein the first seat element further comprises a thirdannular recess; and wherein the first protective sleeve extends withinthe second and third annular recesses.
 5. The gate valve of claim 1,wherein the first protective sleeve defines a fifth interior surface;and wherein the second, fourth, and fifth interior surfaces aresubstantially aligned.
 6. The gate valve of claim 1, further comprising:a first annular seal extending between and engaging the valve body andthe first seat element; wherein the first protective sleeve is adaptedto protect the first annular seal.
 7. The gate valve of claim 1, whereinthe first protective sleeve does not obstruct either the first full-boreinside diameter of the first fluid bore in the valve body or the secondfull-bore inside diameter of the second fluid bore in the first seatelement.
 8. The gate valve of claim 1, wherein the valve body furtherdefines: a third fluid bore intersecting the internal region anddefining a fifth interior surface in the valve body; and a fourthannular recess defining a third annular shoulder in the valve body;wherein the gate valve further comprises: a second seat elementextending within the fourth annular recess and the internal region, thesecond seat element comprising a fourth fluid bore defining a sixthinterior surface in the second seat element; and a second protectivesleeve extending on opposing sides of the third annular shoulder; andwherein the second seat element abuts the valve body.
 9. The gate valveof claim 8, wherein the second seat element abuts the third annularshoulder of the valve body.
 10. The gate valve of claim 8, wherein thevalve body further defines a fifth annular recess, the fifth annularrecess adjoining the fourth annular recess; wherein the second seatelement further defines a sixth annular recess; and wherein the secondprotective sleeve extends within the fifth and sixth annular recesses.11. The gate valve of claim 8, wherein the third fluid bore has a fourthfull-bore inside diameter, the fourth fluid bore has a fifth full-boreinside diameter, and the second protective sleeve has a sixth full-boreinside diameter; and wherein the first, second, third, fourth, fifth,and sixth full-bore inside diameters are substantially equal so that,when a fluid flows through the gate valve, the fluid flows through thegate valve via a substantially constant, full-bore diameter across thegate valve.
 12. A gate valve, comprising: a valve body comprising apassage formed therein along a first longitudinal center axis, thepassage defining an internal region in the valve body, the internalregion defining a first interior surface in the valve body, the firstinterior surface extending about the first longitudinal center axis;wherein the valve body further comprises a first fluid bore formedtherein along a second longitudinal center axis, the first fluid boreintersecting the internal region and defining a second interior surfacein the valve body; wherein the valve body further comprises: a firstannular recess defining a third interior surface in the valve body, thethird interior surface extending about the second longitudinal centeraxis and adjoining the first interior surface; a first annular shoulderdefined in the valve body outside of the internal region and locatedbetween: the first interior surface defined in the valve body by theinternal region; and the second interior surface defined in the valvebody by the first fluid bore; and a second annular shoulder defined inthe valve body outside of the internal region and located between: thefirst annular shoulder; and the second interior surface defined in thevalve body by the first fluid bore; wherein the gate valve furthercomprises: a first seat element extending within the first annularrecess and the internal region, the first seat element comprising asecond fluid bore defining a fourth interior surface in the first seatelement; a first annular seal extending between and engaging the valvebody and the first seat element; and a first protective sleeve extendingon opposing sides of the first annular shoulder.
 13. The gate valve ofclaim 12, wherein the first fluid bore of the valve body has a firstfull-bore inside diameter, the second fluid bore of the first seatelement has a second full-bore inside diameter, and the first protectivesleeve has a third full-bore inside diameter, the first, second, andthird full-bore inside diameters being substantially equal.
 14. The gatevalve of claim 12, wherein the first protective sleeve defines an insidecircumferentially-extending surface and an outsidecircumferentially-extending surface radially spaced from the insidecircumferentially-extending surface; and wherein the first protectivesleeve is devoid of any openings extending radially therethrough fromthe outside circumferentially-extending surface to the insidecircumferentially-extending surface.
 15. The gate valve of claim 12,wherein the valve body further comprises a second annular recessadjoining the first annular recess; wherein the first seat elementfurther comprises a third annular recess; and wherein the firstprotective sleeve extends within the second and third annular recesses.16. The gate valve of claim 12, wherein the first protective sleevedefines a fifth interior surface; and wherein the second, fourth, andfifth interior surfaces are substantially aligned.
 17. The gate valve ofclaim 12, wherein the valve body further defines: a third fluid boreintersecting the internal region and defining a-fifth interior surfacein the valve body; and a fourth annular recess defining a third annularshoulder in the valve body; and wherein the gate valve furthercomprises: a second seat element extending within the fourth annularrecess and the internal region, the second seat element comprising afourth fluid bore defining a sixth interior surface in the second seatelement; and a second protective sleeve extending on opposing sides ofthe third annular shoulder.
 18. The gate valve of claim 17, wherein thevalve body further defines a fifth annular recess adjoining the fourthannular recess; wherein the second seat element further defines a sixthannular recess; and wherein the second protective sleeve extends withinthe fifth and sixth annular recesses.
 19. The gate valve of claim 17,further comprising: a second annular seal extending between and engagingthe valve body and the second seat element; wherein the secondprotective sleeve is adapted to protect the second annular seal.
 20. Thegate valve of claim 12, wherein the internal region is a cylindricalinternal region; and wherein the first interior surface extendscircumferentially about the first longitudinal center axis.